Application of Protruded Strip Resonators to Design an UWB Slot Antenna with WLAN Band-Notched Characteristic

In this paper, a difierent method for designing a novel and compact microstrip-fed slot antenna with band-notched characteristic for UWB application is proposed. In the proposed antenna, a pair of cross-shaped strips protruded inside an extra rectangular slot in the ground plane are used to crate an additional resonance in higher frequencies. By obtaining this resonance, the usable upper frequency of the antenna is extended from 9 to 14.8GHz which provides a wide usable fractional bandwidth of more than 135%. Additionally, by using a square ring radiating stub with a pair of protruded T-shaped strips inside the ring, a desired frequency band-stop performance has been obtained. Good antenna gain and VSWR characteristics are obtained in the frequency band of interest. The proposed antenna can operate from 3.04 to 14.8GHz for VSWR < 2 with a rejection band around 5.1 to 6GHz to suppress any interference from wireless local area network (WLAN) systems. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range.